


sitting in a tin can far above the world

by you_know_whovian



Category: Marvel Cinematic Universe, The Avengers (Marvel Movies), The Avengers (Marvel) - All Media Types
Genre: Alternate Universe, Alternate Universe - No Powers, Alternate Universe - Space, Everyone Is Gay, F/F, M/M
Language: English
Status: In-Progress
Published: 2021-03-11
Updated: 2021-03-16
Packaged: 2021-03-17 18:40:52
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 8,113
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29970651
Author URL: https://archiveofourown.org/users/you_know_whovian/pseuds/you_know_whovian
Summary: Tony Stark, Steve Rogers, James Barnes, Bruce Banner, Natasha Romanov, and Clint Barton are astronauts on the Ares 3 mission, NASA’s latest manned mission on Mars. But when the mission goes wrong, forcing an abort, Tony gets stranded as the rest of the crew takes off, thinking him dead. (A Martian AU)
Relationships: Bruce Banner/Thor, Clint Barton/Phil Coulson, James "Bucky" Barnes/Steve Rogers, James "Bucky" Barnes/Steve Rogers/Tony Stark, James "Bucky" Barnes/Tony Stark, Maria Hill/Pepper Potts/Natasha Romanov, Pepper Potts/Natasha Romanov, Steve Rogers/Tony Stark
Comments: 11
Kudos: 29





	1. Died on Mars

**Summary for the Chapter:**

> A dust storm. A Mars evacuation. A crewmate left behind.

Sol 6:

Steve Rogers put his hands on his hips and let out a long sigh. Mars was gorgeous. An endless sea of red rock and sand. So very different from Earth, but as the geologist (and captain) of the Ares 3 crew, any opportunity to explore the soils of the Red Planet was beyond exciting.

“You gonna help me dig, Stevie, or just stand there and look at all the rocks?” James Barnes smirked at the Captain, quirking an eyebrow. The effect was lost on Steve, as they were both wearing their EVA suits, the reflective face shields meaning they were unable to see each other’s expressions.

“I’m coming. I’m coming,” Steve responded good-naturedly. “What did you need? This EVA is all for your chemical analysis, right?”

“Yeah. I need at least 20 samples. Tony’s doing a grid 20 meters north of here. Dig down 30 centimeters and make sure you get at least 100 grams per sample.”

“Gotcha.” Steve crouched down, clumsy in his EVA suit, using a hand to balance himself as he began to dig.

“The 30 centimeters is important. Make sure it’s 30 centimeters down.”

“I heard you the first time, Buck.”

“Just reiterating, punk. I know you geologists are fascinated by all the pretty dirt. I need mine 30 centimeters deep.”

Steve reached out and pushed James lightly, barely causing the other man to sway. “Jerk.”

“Hey Stark,” a third voice echoed through their comms, “how’s it going over there?”

“You’ll be happy to know, Barton,” Tony responded cheerfully, “in Grid Section 14-23 the particles were predominantly coarse, but in 14-24, they’re much finer, and should be ideal for chem analysis.”

“Hear that, guys?” Clint laughed. “Tony’s found dirt. Should we alert the media?”

“I’m sorry, Barton, what are you doing today? Making sure the MAV is still upright?”

“Well, I’ll have you know that visual inspection of the equipment is imperative to mission success, seeing as the MAV is the only way all of us are getting off this god-forsaken planet. I’d also like to report: the MAV is still upright.”

Steve sighed. “Tony, you keep leaving your channel open, which leads to Clint asking you questions, and you responding, which leads to all of us having to listen, which leads to me being annoyed.”

“Noted, Captain. Did you hear that, Clint? Cap would like for you to shut your smart mouth.”

“We’d like you to use a different adjective to describe Clint’s mouth,” Bruce Banner muttered over the comms from where he sat at the kitchen table inside the Hab. Natasha Romanov, sitting across the table from him while she monitored the other’s conditions on her computer, shot him a smile.

“Was that Banner insulting me?” Clint squawked.

“Captain, I can shut off their comms from here,” Natasha offered.

Tony tutted. “Romanov, I think we all know that the most important aspect of any successful team is constant communication at—”

“Shut them off,” Steve interrupted.

Natasha punched the corresponding command into her computer. 20 meters away from Steve, well in his line of sight, Tony stood from his work, raising his arms in a ‘what gives’ gesture. Steve watched him shake his fists for a few moments, smiling to himself.

An alarm blared on Natasha’s computer. “Mission update,” she told Bruce. “Captain, you’re going to want to come inside.”

“What is it?”

“Storm warning.”

Steve nodded, despite knowing she couldn’t see him. “I saw that in the briefing this morning. We planned around it, so we’ll be done and inside before it hits.”

“They upgraded their estimate,” she responded. Bruce stood and came around the table, leaning in behind her to get a better look at the screen. “The storm’s going to be a lot worse than they thought.”

All four crew members outside looked up. Steve stood, searching the sky in the direction the storm would be coming from, catching sight of it almost immediately. The others followed his gaze, catching sight of the dark mass in the distance. “Back to base,” Steve ordered. Everyone immediately dropped their work, collecting their tools and completed samples and returning to the Hab.

When they were all inside, Steve stood against the kitchen counter, arms crossed. Natasha was reading key points from the storm report aloud. “It’ll be here in 15 minutes. Currently sustained winds of 100 kph, but it’s gusting at 125.”

“Christ.” Tony shared a worried look with James. “Any idea on predictions?”

Natasha pursed her lips. “We’re on the edge. It’s going to get worse before it gets better.”

“What’s the abort windspeed?” Bruce asked, as the Hab canvas rippled violently with another gust of wind.

“150 kph, technically. The Hab could withstand significantly more, but the MAV would be in danger of tipping at 150.”

“Prepare for abort,” Steve decided. “We can go to the MAV and wait it out. If it becomes a danger of tipping, we take off.”

They went through the Airlock in pairs. Clint and Steve first, the pilot and the captain. Bruce and Natasha went next. James and Tony filed out last.

“Visibility is next to nothing out here,” Steve warned as they grouped up at the airlock door. They were battered with sand as the wind tried to push them off their feet, but they managed to stay upright. “If you get lost, home in on my suit. The wind will get worse away from the Hab, so be prepared.”

He turned and stumbled away, Clint at his side. They followed in orderly pairings, though Tony and Natasha were both being pushed around more roughly. Tony began to fall a few paces behind James when an idea struck him. “Captain,” he called through the comms, “I have an idea for how we can make the MAV more stable, keep it from tipping.”

“How?” Steve grunted back.

“We can use cables from the solar cells to shore it up, acting like guy lines.” Tony had stopped walking, looking around. “The rovers could be the anchors,” he panted. “The real trick would be getting—”

A horrible sound, like metal tearing, cut him off. The next second, a piece of flying debris slammed into Tony, carrying him off away from the rest of the crew.

“Tony!” James cried, whipping around.

“What happened?”

“Something hit him!” James reported. “I can’t see him anymore.”

“Stark, report,” Steve snapped, turning around but waving Clint on to the MAV. No reply came. “Stark, report,” Steve repeated. Silence.

“I can’t find him,” came Natasha’s frantic voice as she attempted to home in on his suit’s telemetry. “He’s offline!”

“Captain,” Bruce chimed in, “before we lost telemetry, his decompression alarm went off.”

“Shit,” Steve cursed. “Buck, where did you last see him?”

“He was three steps behind me, then he was gone,” James replied. “He flew off to the west.”

“Clint, get to the MAV and prepare for takeoff. Everyone else, home in on Barnes. Line up and walk west.”

“Doctor Banner, how long can a person survive decompression?” Natasha asked, voice shaking as she stumbled through the storm.

“Less than a minute,” was Bruce’s choked off reply.

“I can’t see anything,” James said as the crew reached him.

“Start walking. Small steps, he could be prone; I don’t want us to step over him,” Steve commanded. They began to shuffle through the storm.

Clint reached the MAV, forcing the airlock closed against the wind. When it pressurized, he shed his suit and climbed to the crew compartment, sliding into his pilot’s chair. “Captain,” he warned as the system came online, “the MAV’s at a 7-degree tilt. We’ll tip at 12.3.” He rechecked his processes on the emergency launch checklist in one hand, noting he’d followed the procedure correctly on memory.

“Copy,” Steve responded.

“Nat,” James called, poking at his arm computer, “Tony’s bio-monitor sent something before he went offline, but I can’t get it open. It just says, ‘Bad Packet’.”

“It got cut off before it could finish transmitting,” she responded, looking at her own computer. “There’s some data missing, but I should be able to figure out what was sent. Give me a minute.”

“Stark doesn’t have a minute,” Clint offered unhelpfully from the MAV. “Message from Houston, Captain. They scrubbed the mission.”

“Copy,” Steve repeated.

“They called it four minutes ago, Cap. From satellite data they got ten minutes ago.”

“Understood. Continue preparing for launch.”

“I’ve got the raw text,” Natasha cut in. “It just reads BP 0, PR 0, TR 36.2. Banner?”

“Pulse and blood pressure zero,” Banner translated. “Temperature normal.”

They all fell silent for a few seconds. “Temperature normal?” Steve repeated, a note of hope in his voice.

“It takes a while for the—” Bruce let out a muffled choking noise. “It takes a while to cool off.”

“Everyone home in on Clint,” Steve ordered, tone devoid of emotion. “I’m going to look for another minute.”

“Captain, we’re at eleven degrees now.”

“Copy,” Steve grunted. “Are you at pilot-release?”

“I can launch whenever,” Clint confirmed.

“If you start to tip, take off.”

“And leave you behind? No way, Cap.”

“It’s an order, Clint.” Steve blinked away the moisture gathering in his eyes as he shuffled across the ground. The others’ headlamps had already disappeared into the storm. “Nat, could the rover’s infrared find him?”

“Negative,” she responded. “IR can’t get through this dust any better than visible light could.”

“What about proximity radar?”

“That’s meant to see the Avenger from orbit,” Clint argued, “not a tiny space suit through a sandstorm.”

“Try it anyway.”

“What’s he doing?” Natasha asked Bruce and James as they ascended the ladder into the crew compartment.

“He’s desperate,” Bruce said. “He’s grasping at straws.”

“Negative on the proximity radar,” Clint called as they took their seats. “I can barely even see the Hab.”

“Captain, I know you don’t want to admit it, but… Tony’s dead.” Bruce stared straight ahead while Steve refused to respond. “Captain,” he said more firmly.

“Hey,” James hissed, turning as far as he was able to look at Bruce. “What the hell is wrong with you, man?”

“I just lost my best friend,” Bruce replied through the knot in his throat. “I don’t want to lose my captain, too.”

“Shit!” Clint yelled. “12.5, Captain, we’re tipping.”

“Launch,” Steve commanded, turning to look at the MAV.

“I’ve got one more trick up my sleeve, then I’m following orders,” Clint returned stonily. “Get your ass to the MAV.” He brough the Orbital Maneuvering System online and fired it, and a roaring sound echoed through the hull as the MAV began to straighten.

“You’re firing the OMS?” Natasha asked. “The aerodynamic caps will automatically eject, leaving three holes in the side of the ship. That’ll make for a bumpy ascent.”

“Well, I’m not leaving Steve, and a bumpy ascent it better than 32 metric tons hitting the ground.” He watched the numbers on his screen slowly revert, finally reaching 11.8. “Captain, get up here.”

Steve cast one last glance at the sandstorm from the airlock of the MAV, pulling it shut as a part of his brain screamed for him to run out and find Tony, damn the consequences. But he had a crew to think about. He ascended the ladder, strapping into his couch.

“I’m at pilot release,” Clint informed him. “Ready to launch.” Steve squeezed his eyes shut. “I’m sorry Captain, but I need you to verbal—”

“Launch,” Steve said, almost too quietly to be heard. Clint activated the sequence, and the MAV lurched upward.

As they rose in the air, falling slightly off course before the computer fixed their trajectory, they gained speed. As it lost the weight of the fuel, the ship reached maximum velocity, determined by the stress the bodies of the crew could handle rather than the ship’s capabilities. The first stage of the ascent completed, they momentarily felt weightless as the force stopped and the first stage of the MAV fell away to crash into an unknown part of the planet below. The second stage took them into low orbit where the engines cut off.

“Main engine shutdown,” Clint confirmed. “Time after launch: 8 minutes, 14 seconds. On course to intercept with the Avenger.”

It had been a smooth launch, normally a cause for celebration. This time, the silence was broken only by the muffled sobs coming from Bruce. Clint looked over at the empty seat beside him, where their engineer and his navigator would usually sit. Steve stared straight ahead, ignoring James’ hand on his arm and the tears streaming down his cheeks. James clutched at his best friend’s arm, unable to stop the shaking in his own body. Natasha grasped Bruce’s hand, feeling bereft.

No one spoke as they docked with the Avenger and unloaded.

◊◊◊

In Houston, the Director of NASA was giving a speech at an emergency press conference called at the Johnson Space Center. Nick Fury stood in front of a room of press, his Public Relations Director—Hope van Dyne— the Director of the Mars Missions—Maria Hill—and the Avenger Flight Commander—James Rhodes—standing behind him. He glared the room into silence. Despite only having one eye, he managed to do it faster than anyone else who stood up here. Maybe it was his surly demeanor. Maybe it was his title. The world would never know.

“At 4:30 AM Central Standard Time, our team detected a storm approaching the Ares 3 mission site on our satellites. We warned Captain Rogers of the storm, and at 6:45 AM, the storm escalated until we classified it as severe and aborted the mission. Due to Captain Rogers’ quick actions, astronauts Barnes, Banner, Romanov, and Barton were all able to reach the Mars Ascent Vehicle safely and perform an emergency launch, which completed at 7:28 AM.” Fury looked down at the cards in his hands. “Unfortunately, Tony Stark was struck by some debris and killed during the walk to the ascent vehicle. The Captain and four of the crew have connected with the Avenger and are headed home. Tony Stark, however, has died on Mars.” The room erupted, but Fury took no questions, exiting the stage.

◊◊◊

In a mansion in Malibu, three robots beeped at each other, fighting over the tennis ball they were chasing around a lab belonging to one Tony Stark.

“Excuse me, gentlemen,” a British accented voice interrupted, causing all three bots to look up at a camera in the corner of the lab. “I am afraid NASA has just announced mission abort for Sir’s trip to Mars.” The bots beeped excitedly, one (with Butterfingers lettered down his strut) spun in circles. Their father was coming home. “It is not good news,” the voice calmed them, having far too much emotion for an AI. JARVIS cleared a throat he didn’t have. “It would seem that, during the evacuation, Sir was hit by some debris. He won’t be coming home.” The bots continued to stare at the camera. “Sir has died on Mars.”

It took several moments for any of the bots to respond. Finally, the one called DUM-E let out a high-pitched whine that sounded eerily similar to a wail. The one called U wheeled slowly over to the lab table that was the most cluttered with random papers and mechanical parts, laying his claw against the workbench. Butterfingers beeped forlornly, rolling to the door to the lab and looking out, frozen.

Several hours later, there was a noise as the front door of the house opened. Peter Parker, a satellite communications engineer who worked in SatCom at NASA, had been on duty in Houston when the report from the Avenger had come in. When he had gotten off, Pepper Potts, CEO of Stark Industries and consultant to NASA since Mr. Stark’s involvement in their space program, had offered him use of the private jet to go to Mr. Stark’s Malibu mansion.

Peter had been an eighteen-year-old engineering student one year from graduation at MIT when he’d first met Mr. Stark, who had granted him a scholarship to complete his school, and the name of a mission director at NASA. Six months later, Peter had been sitting in an interview room when the Director of NASA had walked in, taken one look at his resume, and hired him on the spot to work with their satellites circling Mars.

Despite the rigorous training Mr. Stark had gone through before his mission, he’d kept in touch with Peter constantly, even inviting him to his mansion to meet his robots and AI a few times and work in his lab. Shuffling into the mansion now, knowing Mr. Stark would never come home again, Peter couldn’t see through his tears.

He slouched into the lab, and was immediately accosted by Butterfingers, who he calmed with a hand on the longest strut. “Mr. Stark—he—I can’t—”

“It is okay, Mr. Parker,” JARVIS said softly, causing Peter to look at the ceiling. He still hadn’t broken the habit, no matter how many times Mr. Stark had reminded him JARVIS didn’t actually live there. “I told them already.”

Peter’s knees went weak, legs giving out. Only Butterfingers’ strut beneath him and DUM-E grabbing the back of his sweatshirt kept him from hitting the floor. They rolled over to the couch, dragging him with them. When he settled, all three bots wheeled close enough to be touching him. “I’m sorry, guys. I didn’t even—I don’t know. I was there when they saw the storm, but we didn’t even know it was bad enough to—to do that until—until they were already launching.” He swiped at his eyes. “If I had been a different kind of engineer, if I had been able to work on the stuff they were sending over there, I don’t know.”

“There’s nothing you could have done,” JARVIS interrupted carefully. “This was not your fault, Mr. Parker.”

“I know,” Peter sobbed. “In my head, I know that. But—but in my heart,” he clutched at his chest, feeling like he couldn’t breathe, “in my heart, I feel like I disappointed him. Like he never—he never—”

A light flickered, and then the far wall of the lab was covered in a projected video. It was Mr. Stark.

_“Hey, J, have you seen this photo?” He was staring at his computer screen._

_“The satellite photograph on the NASA website?”_

_“Yeah, that one. Did you know Pete was the one who captured it? I mean, I know the satellites do the whole picture thing by themselves, but he controls where they go. He got that picture. It’s so—” he waved his hands in the air to express something he couldn’t put into words._

_“It is a lovely photograph, Sir,” JARVIS responded._

_“He did photography in high school, did you know?”_

_“Yes, Sir.”_

_“That kid is the best thing to have ever happened to me.” His voice was softer, like the look in his eyes. “I wouldn’t have made the Ares 3 mission without him, and I’m not sure I would still be sober without that program.”_

_“He is very good for your mental and emotional health,” JARVIS noted._

_“Send him a text for me? Ask if he wants to come out to the mansion on his days off this week. We’ll go to the beach and a few bars, and I’ll see if I can finally get him a date.”_

The video froze on a picture of Tony smiling at his computer, eyes shining. Tears were now streaming nonstop down Peter’s face as he took in the image. “He stayed sober for Ares?”

“He stayed sober for you,” JARVIS corrected. “It is not an over-exaggeration to say that, without your influence in his life, Mr. Stark may well have never gotten to go to Mars. There is a good chance he would have died right here, too drunk or high to work his heavy machinery properly.” Peter let out a sob, clinging to the bots as they beeped concernedly at him. “At least he got to see the stars,” JARVIS said so softly it sounded like a sigh. “Sir has always belonged among them.”

◊◊◊

Sol 7:

Tony woke to the shrill beeping of the oxygen toxicity alarm of his EVA suit. He pushed himself up to a sitting position, noting with a detached manner the sharp pain in his abdomen. Shaking the sand off his face shield, he looked around the barren expanse of Mars, locating the Hab in the distance, near enough that it would be an easy walk. Glancing around even more, he realized what he wasn’t seeing—the MAV. He looked up, realizing what that meant. The crew had gotten to the MAV, thinking he was dead, and had taken off to meet the Avenger and return home. He was stranded on Mars. Alone.

“I am so fucked.”


	2. Chapter 2: Botany Powers

**Summary for the Chapter:**

> A new friend makes an appearance. Tony decides not to die on Mars.

Sol 7:

Tony took stock. When he tried to stand, dusting sand from himself, he was immediately brought to his knees by the sharp tugging in his abdomen. Looking down, he saw its cause was a long strip of metal—an antenna from the communications array, Tony’s mind supplied helpfully—that had run him through. Well, not all the way.

It had only punctured his front, breaching his suit to be stopped by his pelvis. Other than that, and the annoying oxygen toxicity alarm that would not _shut up_ , he was in fine enough shape to stumble back to the Hab. Anything else could be considered when he was no longer acting as a human pin cushion.

It didn’t take long for him to cut through the line connecting the antenna in his stomach to the communications array and stumble to the Hab, but he only had a short while breathing levels of oxygen that high before he died from too much of it. Kind of ironic—the man stranded on Mars with a leaky spacesuit might die from too much oxygen.

“You see,” Tony explained to an empty planet to distract himself from the pain as he dragged his feet across the sandy terrain, “when an EVA suit breaches, it automatically begins filling with Nitrogen from its tanks until the wearer can patch it up. It seems like the tear in my suit sealed up just fine with all the blood clotting and freezing at the puncture site, so that’s not an issue. But it would seem,” he took a pause, panting as he maneuvered around a boulder, “that I was out long enough to use up my CO2 filters, which is bad. CO2 poisoning is a quick and unpleasant way to go. The suit won’t have that.” Only twenty meters from the door now. “So, it begins what we refer to as “bloodletting”, meaning it lets out a tiny amount of air from the suit and backfills with Oxygen and Nitrogen. My Nitrogen tanks are out, so my suit has just been filling itself up with pure Oxygen for who knows how long now.”

He checked the computer on his arm. “I’m at 80 percent Oxygen. For reference, the Hab—and Earth’s atmosphere—are only around 20 percent. These levels are high enough to seriously damage my body, but I’ve got a little time before that starts to happen. And look at this!”

He let out a little whoop of excitement as he reached the door to Airlock 1. He pulled open the door and went inside, waiting for it to pressurize before exiting into the Hab.

The Hab was the living center for the astronauts in the Ares 3 missions—the third of what was currently planned to be 5 manned missions NASA had sent to Mars. It was a bit short of 100 square meters of space, with a kitchen, a small lab, bunks, and all the vital pieces of equipment a crew of 6 would need to live for 31 days on a planet millions of miles away from Earth.

As Tony stumbled over to the cabinet where all of the medical supplies were kept, he thanked the stars that he had paid attention when they’d been learning basic medical training. He removed the antenna quickly, keeping pressure on the wound as he doffed his EVA suit, and after a quick shot of local anesthetic, some irrigation, and a few stitches, he relaxed back into the desk chair wrapped up in a blanket. They had performed emergency evacuation shutdowns, which meant the life support systems were still functioning, but the computers had been powered down.

Tony flipped them on, waiting for them to warm up. “Boss?” an Irish voice greeted him as the computer screen prompted him to log on.

“Hey, FRIDAY.” When Director Fury had contacted him personally to let him know he would be on the crew for the Ares 3 mission, Tony had pulled the backup AI from the back of his desk drawers and cleaned her off. She didn’t have anything near the level of humanity or even power as JARVIS, but she made life a little easier on the Avenger (the massive spaceship that carried the Ares crews between Earth and Mars) and then in the Hab.

Fury had agreed to let Tony bring her only after he had worked his way up the chain, convincing first Steve as the Captain, then Rhodey as the Flight Commander (though that hadn’t been difficult, as Rhodey trusted him with everything except planning birthday parties which had been _one time, Rhodey, come on, it wasn’t even that big of an explosion_ ), then Maria Hill as the Mission Director, and finally Fury himself of FRIDAY’s potential usefulness.

“Where is the rest of the crew? I thought Captain Rogers made the order to abort the mission. I can’t contact the MAV.”

“They, uh…” Tony rubbed the back of his neck. “The rest of the crew got to the MAV. The reason you can’t contact it is because they took off. I’m assuming—I’m hoping they made it to the Avenger, in which case they’re probably out of orbit by now and headed home.”

“Why did you not get on with them?”

Tony lifted the blanket aside to show the camera the bandage on his side. “I got hit when the communications array snapped. An antenna tore through my bio-monitor computer, so the crew all saw my stats go to 0. They thought I was dead. Steve made the right choice to get everyone else off planet.” He stared at the screen, covered in all of the measurements and recordings he had been working on before their last EVA on sol 6. “FRI, will you run diagnostics on all of the life support systems in the Hab?”

“Checking them now.” It took a few minutes for her to finish. “All in perfect working order,” she confirmed.

“I think I’m going to go sleep,” Tony mumbled, standing from the desk and stumbling toward the bunks.

He was in a Hab designed to last 31 days. He had only a finite supply of food. If the water reclaimer broke, he’d die of thirst. If the Oxygenator broke, he’d suffocate. If the Hab breached he’d just sort of… implode. If none of those things happened, he’d eventually starve. He had no way to contact NASA, and no plans yet as to how he would get home.

He just needed to sleep. He’d get to work in the morning. A soft, “Goodnight, Boss,” was the last thing he heard before drifting off.

Sol 8:

“Okay, FRIDAY,” Tony started off, pulling out a protein bar for his breakfast, “so things look significantly better this morning. I still don’t know how to contact NASA, and I’m still in deep shit if anything breaks down completely, but I’ve figured out how I’m going to get home. In 4 years, the Ares 4 missions will be landing on Schiaparelli crater. It’s only 3200 km away from here. All I have to do is figure out how to survive long enough to be there when they arrive.”

“What’s the first order of business, Boss?”

“First is food,” Tony announced, rolling the desk chair into the kitchen with a good push and taking a bite from his protein bar. “We were supposed to be here for 31 sols. We were 6 sols in when it all went to shit. For redundancy, NASA sent 60 sols of food in the pre-supply probes—in case a probe or two malfunctioned, we wouldn’t have to totally abort the mission. That leaves 54 sols worth of food left for 6 people. I’m just one, which gets me over three hundred sols—without rationing. If I ration, I can probably make it to 450 sols, which is one and a quarter years. Tell me if my math is right, FRI.”

“You’re on track, Boss.”

“Great. So, everything else—water and oxygen—I can continue to have so long as I can repair whatever may go wrong with the Reclaimer and Oxygenator. If I can manage to get myself an extra three years of food, I can do it.” Tony tapped his fingers in a quick tattoo on the table. “The problem that arises, however, is that I have to grow three years of food on a planet where nothing grows.”

He stayed quiet for a minute as he pondered the issue at hand, pushing himself around the Hab on his rolling chair. His feet hit the floor, skidding him to a stop, when he saw the booklets each crewmember had prepared for the trip with their list of duties and experiments laid out. “Brucie bear, I have never been so glad for you in my life,” Tony breathed as he flipped through the packets until he found Bruce’s.

Each member of the crew had specified duties. Steve was a Captain and a geologist. James was a chemist and the EVA specialist. Romanov did her thing with computers and the nuclear engines the Avenger used to carry the Ares crews from Earth to Mars and back. Clint was the pilot. Tony the engineer. Bruce was the ship’s doctor, but when he wasn’t being the doctor, he was a botanist.

Because of the uncertainty of space travel, each crew member was expected to learn as much as possible about one other area of expertise—in case they lost someone, or an experiment took two. James had been the backup engineer for Tony. Bruce was the backup chemist for James. And Tony… well, Tony had shadowed Bruce for months to learn everything he could about botany. Seeing as how Tony Stark was a genius, “everything he could” was a whole damn lot.

“FRIDAY,” Tony called to the AI, not looking up from the pamphlet, “I’ve got a solution.”

He went to the kitchen and pulled out a box marked ‘DO NOT OPEN UNTIL THANKSGIVING’. The holiday was supposed to have happened during their time on Mars, and some psychologists had suggested that it would be good for crew morale if they prepared and ate a real Thanksgiving dinner together. So, NASA had decided to make an exception to the—in Tony’s opinion—frankly unsuitable protein bars and freeze-dried packets of food the crew ate while on the mission. They had sent along a vacuum-packed Thanksgiving meal. In it, Tony found some peas, plenty of beans, and—to his delight—twelve potatoes. Not frozen, not mulched, just refrigerated. They had traveled with the crew as in-pressure cargo specifically for the special Thanksgiving meal.

Tony let out a crow of victory, a plan already forming in his mind. “FRIDAY,” he said with a laugh, dropping the potatoes back into the box so he could go back to the desk and start running some calculations, “we’re gonna make it. Mars will come to fear my botany powers.”

Sol 9:

He’d spent all day yesterday working on the plan. He’d done some math, run his numbers by FRIDAY, and reached a problem he didn’t have to focus to solve. His entire body was aching from having been flung around on Sol 6, and he was getting dizzy spells by mid-afternoon, at which point FRIDAY blocked his access to the computer monitors until he went and made himself dinner.

The last two and a half years, he’d been living or working with other people on almost a daily basis. It had been a far cry from his usual solitude in a lab. In that time—particularly the half year living on the Avenger with the other members of the Ares 3 crew—he’d had people reminding (read: forcing) him to sleep eight hours every night and eat three square meals a day. When he’d pointed out the hypocrisy of monitoring his sleeping habits when not a single one of the crew regularly slept through the night, Steve had only raised a stern eyebrow and said, “Everyone else at least tries.”

Now, he’d been alone for only 2 sols, and already he was beginning to revert to his ‘eat when hungry, sleep when on the verge of collapse’ methods. FRIDAY had forced him to bed at a reasonable hour the night before by turning off all the lights in the Hab except the ones by the crew’s bunks. He’d been more tired than he realized, falling asleep almost as soon as he’d pulled the blanket up over his head.

This morning, though, Tony had decided to stretch his legs and take stock of what he had left before attempting to solve the problem of feeding himself for 4 years again. So, he donned his EVA suit and made his way through the airlock. The first order of business was cleaning off the panels in the solar farm. They’d been largely covered in sand the day of the storm, but there were enough of them that the decrease in power hadn’t really registered within the Hab’s systems yet. It only took about an hour to blow off all the sand and right the few panels that had fallen over in the storm.

After an extra forty minutes walking around to see what else remained, he was clutching the wound in his stomach as he hobbled back toward the airlock. Walking around in the Hab may have been fine, but a 50 kg EVA suit was a little too much. When he entered the Hab with his hand against his abdomen, FRIDAY immediately caught on.

“There’s painkillers in the med bay, Boss.” Tony shed his EVA suit and trudged over to the ‘med bay’. The couple of boxes of medical supplies stared back at him while he considered his choices. “It’s the second box from the left,” FRIDAY prompted.

“Yeah, baby girl, I know. I’m just…” He blew out a gusty breath, taking his time, before finishing, “I’m just thinking, FRI.”

“What about?”

“If I can do this.” Tony had been a bit of a party kid during his teenage years. At MIT, he’d been so much younger than everyone else that he’d done whatever they suggested to seem cool and make friends. It hadn’t taken long for him to get hooked on the drugs and alcohol everyone had been pushing on him, and even after Rhodey came along and steered him away from the worst of it, it had been hard to quit. He’d given up the drugs after his parents died, because they didn’t make him stop hurting in the weeks after the crash. He’d almost given up the alcohol, too, seeing as his father’s drunk driving had been what caused it.

But once he’d gotten out of college and Rhodey had left for his first tour, Obie was the only person he kept regular contact with. And though his godfather always said he wanted Tony in top form to keep spitting out new ideas for the company, he’d never kept away the bad influences that flounced into Tony’s life for the fame or the money. It wasn’t until Afghanistan that he’d stopped drinking every day. He hadn’t blacked out since his stint in the desert, not even when the Palladium was killing him.

The new direction he’d given his company—away from weapons and into clean energy and space travel—had given him something to care about beyond the next 24 hours. When the possibility of getting to be an astronaut and joining the Ares crew had arisen, he’d stopped drinking altogether (though that was in no small part due to the kids he’d somehow become a mentor to along the way).

Now, thousands of miles away from home, alone, and trying desperately not to die, Tony wondered what the effects of an opioid like Vicodin would have on him. Could he trust himself to only use it when he absolutely needed it? What would happen if he started taking it and he couldn’t stop?

He shook his head. “Not today. The pain’s not that bad, anyway.”

“Boss, your heartrate is showing—”

“I’ll be just fine in a minute, FRIDAY,” Tony insisted, moving away from the meds to collapse at the desk. “Can you bring up a new document and start making a list of all of the supplies I’ve got?”

“At the ready, Boss.”

“The MAV is gone, but we knew that already. The landing stage is still there, which means I’ve for the landing gear and the fuel plant.” The words _Mars Ascent Vehicle: Landing Gear, Fuel Plant_ appeared on the document. “You wouldn’t happen to have blueprints for any of that, would you, FRI?”

“I’m afraid not, Boss.”

“Didn’t think so.” Tony chewed on his lip, reaching out on autopilot for the magnetic beads he kept in his little box at the desk.

He rolled them around, squishing the tiny ball bearings between his fingers and then bunching them up again. It had been a present from Natasha about a month after she had become a semi-permanent fixture in his life. _“You can’t bring all your bits and bobs into space, and I doubt you’ll be able to tinker with whatever metal and heavy equipment they send to Mars. It’s best to find another way to keep your hands busy so your mind can work.”_ She’d just dropped the little package in his hand and then never spoken about it again, but she’d been right. He’d had to train himself out of reaching for a screwdriver and the nearest piece of equipment when he’d been told he would be on an Ares mission. The NASA scientists frowned upon taking apart water reclaimers and oxygenators just because one was bored. The magnetic beads could squish, clack, and be shaped to Tony’s amusement, meaning they kept him entertained enough to keep him from going crazy without his usual lab equipment available.

“I don’t know a whole lot about the fuel plant except what its function is,” Tony admitted to his AI. “Since the MAV is sent here years ahead of the mission, it has the fuel plant to make its own fuel. It takes 24 months to make all the fuel, so NASA gives it 48 just to be safe. The Ares 4 MAV is actually on site already. I watched Clint land it before we all got in the MDV to come down to the surface.

“Speaking of which, I’ve got the entirety of the MDV. It’s not in great shape, what with the whole hurtling toward the ground in a descent controlled only by Clint and a few parachutes, but I can use it for scraps. Plus, there’s plenty of fuel left—Hydrazine, specifically—since Clint landed it so well.”

Not that Tony had told the pilot he’d done a good job on the day of the landing. The descent from the Avenger to the surface of Mars in the MDV was perhaps the most terrifying 20 minutes of Tony’s life—and that includes the whole of his time in Afghanistan. Essentially, they had detached from the Avenger and started dropping toward Mars. It had been all smooth sailing until they’d hit the atmosphere. If you thought turbulence on a jet going 720 kph was bad, the feeling of a tin can going 28,000 kph was indescribable. It hadn’t been pretty, but Clint had actually managed to get them within 9 meters of target, which was rather impressive. Instead of congratulating Clint (upon meeting each other, the two had decided to be mortal frenemies—Clint’s words—and a compliment was out of the question), Tony had compared the trip to a poorly made wooden rollercoaster and pretended not to laugh while Bruce turned green and tried not to puke.

_Mars Descent Vehicle: Hydrazine, Scraps_ was added to the list. Tony tapped his fingers in a quick tattoo against his chest, where the arc reactor had once sat years ago. “No luck on finding the satellite dish. Probably got blown several kilometers away, and I’m not about to waste EVA time looking for it. That means no communication with the weather stations, and definitely no way of talking to NASA. Speaking of EVAs, though, I’ve got roughly 1500 hours of CO2 filters left. If I’m going to be hanging around here for 4 years, I can’t be making any unnecessary EVAs.” FRIDAY added the CO2 filters to the list. “The solar farm is in fine shape; it’ll just need some routine cleaning. The rovers are in perfect working order, if a little buried after the Sol 6 storm. That’s all from outside.”

As FRIDAY added the last things to the list, Tony looked around the Hab to determine what would go on the list of supplies he had inside. “We’ve got the count on food. I’ve got plenty of water and air in here. Put down the vitamins we found yesterday.” Going through the food last night to decide what he wanted for dinner (flash frozen chicken or a protein bar), Tony had found enough vitamins to last him for about 8 years. At this point, when he starved, he’d have a perfectly balanced array of vitamins and minerals, just no calories.

“What’s next?” FRIDAY asked when he’d been quiet for too long, lost in thought.

“The next problem is the same one we ran into yesterday.”

“The Calorie Conundrum?” FRIDAY pulled up a different document—the one she’d been using to keep track of Tony’s calculations the night before.

“The very one.” Tony rolled closer to the desk to examine the screen. They’d decided that in order for him to stretch his food supplies until Ares 4, he’d need to grow 1000 calories worth of food per day, keeping him at a cool 1500 calories to eat daily. The potatoes gave him about 770 calories per kilogram. Unfortunately, the Hab was only 92 square meters, which wasn’t enough space to grow the number of potatoes he would need. “We need more space to farm.”

“Where will you find it?”

“I’ve got a couple of ideas. I’ve got 5 spare bunks, 2 spare lab tables, and 2 pop-tents. That’s 2 square meters per bunk and table, and 10 per tent. That gets me to…” he did some quick math in his head, “126 square meters of farmland.”

“A little short, still, Boss.”

“But enough to keep me living. Especially if I grow everything more efficiently. I figure with individual attention, warmer weather—we’ll crank the Hab’s temperature up to a toasty 25.5 oC—and no pests, I can get a 40-sol growth period. Doubling up the planting space can get me more potatoes in the same amount of time. Normally, that would turn farmland into a dustbowl in a decade, but I don’t need a decade, so we’ll risk it. All of that should get me to roughly 900 calories a day.”

“That’s still not enough,” FRIDAY worried.

“It’ll be fine, FRI. I’ll only have to starve a little bit to make it to the Ares 4 landing date.” Tony sighed, rubbing his face.

“If we’re going to make it, then why do you seem upset?”

“The real issue is making enough soil to cover the Hab. Bruce brought along a little bit of soil, but we’re talking a windowsill planter. Not 13 cubic meters, which is roughly what I’ll need. Also, each cubic meter of soil needs about 40 liters of water to be viable, so we’re talking 500 liters of water. I’ve got 300 liters in case the water reclaimer were to break, and I want to keep 50 just in case. So, not only do I need to get 13 cubic meters of viable soil, I need 250 more liters of water to make sure I can farm in it.”

“Any ideas?”

“One,” Tony snorted out a laugh. “It’s not pretty.”

“Care to share?”

“Shit.” He smiled sunnily up at her camera. “Literally. The Hab’s toilets seal our shit into tiny little bags when we use the restroom. They’re little vacuum dried bags meant to be discarded. They don’t have the bacteria we’ll need for the potatoes anymore, but they do have the complex proteins that Martian soil is missing.”

“Then how will you get the bacteria?”

“Bruce’s soil. I can’t cover the whole area right away, but I can mix in the earth soil Bruce brought with some of the Mars soil and our waste. If I give it a few days, the bacteria will spread like… well, like a bacterial infection. Once it’s spread, I double the soil with more Martian dirt. Rinse and repeat until I’ve got all my farmland.”

Tony sat back, arms spread wide. “You’re right, Boss. That isn’t pretty. But it works.” Tony’s smile softened as the numbers ran themselves out on the computer screen—the amount of soil he would need before he could start, how much soil each doubling would take, and how long it would take him to make enough soil to cover the Hab. He was about to ask if she had any estimations on the amount of waste the toilets would have collected in six sols when his stomach growled.

Immediately, the computer screen turned off. “FRIDAY!” he protested.

“Food first,” she sniffed, “then science. Your pain levels have not decreased since you sat down.” Tony waved her off, standing, then sat quickly back down as a flare of pain went through him and his vision began to dance with spots. “No more science today,” FRIDAY commanded. “You’re taking a nap after lunch.”

“You’re not the boss of me,” Tony mumbled. In the silence that followed, he could feel the pressure of FRIDAY’s watchful eye as though she was standing in the room with him. “I think I’m going to take a nap after lunch,” he decided quickly. “But not because you said to. I’m just a little tired from all of my work this morning.”

She stayed silent while he heated up his food, although the atmosphere in the Hab had definitely become one of smug superiority. As he sat at the table with his food, he asked her, “Do you know what media everyone brought on their computers? Mine was mostly information for your systems, so I don’t have any movies or music. I know everyone else was stocked up, though.”

“I do not know for sure beyond some movies of Ms. Romanov and Captain Roger’s music collection, Boss.”

Tony had to chuckle at that. Steve had a penchant for bad 70s music and the rare 80s pop hit. When he was running experiments in the Hab and everyone else was safely indoors where comms were unnecessary, he put on his headphones and bopped around his little lab set-up. Tony had spent countless hours pretending to work within sight of him, smiling a secret smile to himself at Steve’s terrible dance moves. Or, sometimes, sharing not-so-secret smiles with James as they recorded what Natasha had taken to calling “the Captain’s jam sessions”. The first time Steve had caught them in the act, they had barely convinced him to let them keep the video.

_“For science!” Tony had pleaded, grabbing wildly for the tablet Steve was holding too high in the air for him to reach. “Please, Steve, the world needs to know!”_

_“For science?” the Captain had repeated, eyebrow raised._

_“For posterity, Stevie.” James had corrected, throwing an arm around Tony’s shoulder so they could give the Captain the combined power of their puppy-dog eyes. Steve had caved in less than 5 seconds._

Tony stood from his chair, grabbing up the very same tablet on his way to the kitchen. “A few minutes of Cap’s dancing and a couple of hours snooping through everyone’s hard drives ought to be a good use for my afternoon, don’t you think, FRIDAY?”

“I couldn’t agree more, Boss.”

**Author's Note:**

> Hey folks! This is my first fanfic, so I'd love any kudos/comments!
> 
> If you've read the Martian or seen the movie, this probably seems pretty familiar. I'm keeping largely to the plots of the book/movie, but there will be a lot of Avengers character time that isn't given to the characters in those.
> 
> I plan to update regularly (mostly week-by-week). I hope you enjoy!


End file.
